The present invention generally relates to a cleaning arrangement, and more particularly to a cleaning device used for removing residual toner on an image support member, for example, in an electrophotographic copying apparatus or the like.
Conventionally, a cleaning device for removing residual toner from the surface of an image support member in a copying apparatus or the like is arranged to effect the cleaning by causing a blade of a rubber material or the like to contact, under pressure, the surface of a photosensitive member such as an image support member for scraping off toner therefrom, or by rotating a roller of silicone rubber or the like contacting the photosensitive member or photoreceptor drum under pressure for removal of the toner. Although these known practices are superior, with the construction thereof generally simple, there is such a disadvantage that cleaning becomes imperfect due to slippage of toner between the blade and the surface of the image support member or fusion of toner undesirably takes place on the surface of the photosensitive member due to pressure exerted between the blade or rubber roller and the photosensitive member as the toner becomes spherical in shape and smaller in the particle size thereof as in the recent tendency.
In order to overcome the disadvantage as described above, there has also been proposed an arrangement in which a rubbing member in the form of a belt is adapted to rub against the photoreceptor drum for the image support member, over a predetermined width.
By way of example, the cleaning device disclosed in Japanese Patent laid-Open Publication Tokkaisho No. 61-121076 is so arranged that, with a belt-shaped rubbing member contacting the surface of a photoreceptor drum under pressure, said rubbing member is moved at a speed different from that of the photoreceptor drum or stopped at the contacting position therebetween so as to rub against the photoreceptor drum surface, thereby to clean off corona products adhering to the surface of the photoreceptor drum as an image support member by the rubbing thereof. Meanwhile, the cleaning device described in Japanese Patent Laid-Open Publication Tokkaisho no. 62-11883 is provided with a belt-like cleaning sheet having a large number of projections on its surface for scraping off residual toner and movably disposed with respect to the photoreceptor drum surface so as to effect the cleaning by causing said cleaning sheet to contact said drum surface.
Each of the known cleaning devices as referred to above has a superior performance, since the contact area between the belt-like rubbing member and the image support member may be increased without being restricted by the material or hardness of the member to be pressed against the photoreceptor surface.
Incidentially, for depressing a such belt-like rubbing member onto the surface of the photoreceptor drum, it is generally required to pass the endless belt-like rubbing member around three rollers disposed to form a triangle, with the rubbing member between two of the three rollers being pressed against the photoreceptor drum surface to increase the contact area, and thus, the device inevitably tends to become large in size.